Referring to FIG. 1, a conventional hand truck includes a truck frame 11, as well as a toe plate 13 and a wheel unit 12 disposed on a lower end of the truck frame 11 at front and rear sides, respectively. The truck frame 11 has two upright columns 111, a plurality of crossbars 112 interconnecting the upright columns 111, a mounting plate 113 interconnecting the crossbars 112, and a U-shaped hand gripping rod 114 interconnecting upper ends of the upright columns 111. The wheel unit 12 has a wheel axle 121 connected to the mounting plate 113 and extending in a left-and-right direction for pivotably connecting two wheels 122 at two ends. The toe plate 13, which is of an L-shape, has vertical and horizontal plate portions 131, 132. Several stacked objects (not shown) can be set on the horizontal plate portion 132, and the truck frame 11 can be tilted to be pushed or pulled by an operator. It is desired to provide a weighing device to readily measure the weight of the stacked objects loaded on the hand truck without the need to remove the objects from the hand truck.